Temperature sensor PT100

Platinum resistance thermometer (PRTs) provide excellent accuracy over a wide temperature range (from –200 to +850 °C). Unlike thermocouples, it is not necessary to use special cables to connect to the sensor. The principle of operation is to measure the resistance of a platinum element. PT100 has a resistance of 100 ohms at 0 °C and 138.4 ohms at 100 °C. The relationship between temperature and resistance is approximately linear over a small temperature range. For precision measurement, it is necessary to linearise the resistance to give an accurate temperature.